Reservoir EngineeringWell Performance
Prats High-Conductivity Fracture Effective Wellbore Radius Formula
Prats High-Conductivity Fracture Effective Wellbore Radius calculates effective wellbore radius for well performance workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (X_f, r_w) are known and the assumptions behind the cited well performance relationship match the engineering case being checked.
Assumptions
- Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
- The declared units match the field-unit constants used in the formula.
- The cited formula applies to the selected petroleum engineering workflow.
Limitations
- The calculation does not replace a full engineering model or operating procedure.
- Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.
Common mistakes
- Mixing unit systems without converting the inputs.
- Using default example values as field recommendations.
- Applying the formula outside the source assumptions.
Default example
Using the default inputs, r_we equals 150 ft.
X_fft
300
r_wft
0.328
Inputs
X_f
ftFracture Half Length
r_w
ftPhysical Wellbore Radius
Outputs
r_we
ft
Effective Wellbore Radius
S_f
dimensionless
Equivalent Fracture Skin Factor
X_f
ft
Fracture Half Length
r_w
ft
Physical Wellbore Radius
Source and review
reviewedPrats, M., Hazebroek, P., and Strickler, W.R. 1962; Pengtools Prats effective well radius summary.
Source